How to replace string with regex in jQuery Javascript in Html with Using nodeType / node Shortcode

How to replace string with regex in jQuery Javascript in Html with Using nodeType / node

Text

[jems-countdown token="4" data-id="20136582"]

Script

jQuery(document).ready(function(){
   
    $('body *').contents().each(function() {
        if(this.nodeType == 3) {
            var u = this.nodeValue;
            var reg = /\[(jems-countdown.*)\]/g;
            $(this).replaceWith(u.replace(reg,'<div class="metcounter" $1>kanasagra</div>'));
        }
    });
  });